To use Unity with Docker, you can try this Guide:
{% embed url="https://docs.edgegap.com/docs/tools-and-integrations/unity-server-in-docker" %}
Additionally, our friend Andrew Allbright shared a sample with Mirror running on Docker + Docker Compose:
The Mirror server is built as a dedicated linux server build and runs on an ubuntu server. The webGL assets are served from an nginx server. Another nginx container serves as a reverse proxy, so that the websocket connection is accepted.
{% embed url="https://github.com/aallbrig/unity-mirror-networking-containerized" %}